This invention relates to a peritoneal catheter device for dialysis or the like treatments in the abdominal cavity.
Peritoneal catheters for dialyses have been known and used alternatively to the extra-corporal dialysis. As an example, known is a peritoneal catheter for chronic peritoneal dialysis, which is denoted "Torelli-Valli" from its inventors. Said catheter comprises essentially a perforated cylindrical rod, hollow inside, which is connected to equipment operative to introduce a dialysing liquid into it. The operation mode of that peritoneal catheter provides for the insertion of the same, either in a permanent or semi-permanent way, within the abdominal cavity, and the intermittent delivery of a dialysing liquid to the catheter. The dialysing liquid enters the abdominal cavity through holes formed in the catheter wall, and is withdrawn from the abdominal cavity through those same holes, thereby its operation cycle is a discontinuous and alternating one.
Inside the abdominal cavity, the dialysing liquid will effect the required interchange with blood at the abdominal capillaries which, in this case, take the place of the filtering membranes employed in extra-corporal dialyses.
To achieve maximum dialysis effectiveness, it is expedient for the dialysing liquid to intimately contact all of the abdomen recesses, including bends, to thereby increase as mush as possible the amount of blood exchanging, through the semipermeable membranes of the capillary vessels, and by osmosis or diffusion, its substances to be purified with the purifying substance contained in the dialysing liquid.
The process just described has the very important advantages of utilizing for the semipermeable membranes those naturally provided by the human body, instead of artificial ones, and that no blood is drawn off the normal circulatory system. Furthermore, the same dialysing liquids can be used as in extra-corporal dialysis.
Such significant advantages bring about further a significant simplification of the dialysis promoting equipment, which is only required to renew the dialysing liquid, and of the procedure, as well as in lower patient treatment costs, so that a higher number of patients can be treated.
However, the above advantages are somewhat counteracted by certain limitations. In fact, the available exchange surface area is, in conventional devices, restricted because defined by the surface areas of the blood vessels located in the neighborhood of the catheter. Quite serious is then the reduction of the dialysis efficiency which results from the aforementioned discontinuous and alternating type of operation, which involves both idle time and the need to let the dialysing liquid flow twice through one abdomen portion, with the attendant risk that the direction of the reactions is reversed.
An added drawback of conventional catheters is that their outflow and inflow ports are likely to become clogged owing to the catheter being positioned in close contact with intestine bends.